Expansion type connector plug



p 9, 1958 YR. KOCH 2,851,669

EXPANSI'ON TYPE "CONNECTOR PLUG Original Filed May a, 1949 Y m m H 4 0 6 N 4 3 D M MM/ A H C m UnitedStates Patent EXPANSION TYPE CONNECTOR PLUG Richard C. Koch, Indianapolis, Ind.

Original application May 6, 1949, Serial No. 91,771. Dlivided and this application June 21, 1955, Serial No. 6,894

5 Claims. (Cl. 339-75) This invention relates to improved electrical connecting means and is a divisional application of my U. S. application Serial No. 91,771, filed May 6, 1949, and entitled Electrical Connecting Means, now abandoned.

One of the objects of this invention is to provide an improved electrical plug connecting means of the socalled banana type for assembly in the socket of a jack in order to permit multiple electrical connections.

A further object of this invention is to produce an improved electrical connector member of the banana plug type wherein the male end may be locked in a cooperating receiving socket of a jack.

Another object of this invention is to provide improved means for spreading the split sections of the male end of a connector plug so that said sections can be locked at will when pushed into the receiving socket of a jack.

' Finally, it is an object of this invention to provide an improved plug connector permitting multiple electrical connections and simple and efficient means for locking the male end of the plug in the socket of a jack assembly.

Other objects of the invention will become apparent from the following. description taken in conjunction with the accompanying drawings wherein like numerals represent similar parts throughout and wherein:

Figure l is a slightly enlarged longitudinal view, in cross section through the socket portion, of'a connector plug for making a multiple connection at a jack;

Figure 2 is a longitudinal sectional view through a plug-jack assembly which is so constructed that the split sections of the male projecting portion of my novel plug may be expanded to lock it in the jack socket, said plug being shown as positioned in the socket but expansion is not established;

Figure 3 is a view partly in section of the plug illustrated in Figure 2, but showing the position of the parts when the split sections are expanded; and

Figure 4 is a sectional view taken on the line 4-4 of Figure 3, showing the manner of connecting the bare end of a conductor to the plug ahead of its socket.

Perhaps it should be stated at the outset that the invention is not limited in its application to the details of construction illustrated in the drawing and the phraseology and terminology employed herein is for the purpose of description and not of limitation.

Referring to the drawings in detail and first to Figure 1, there is disclosed a typical connector plug of the socalled banana type. This connector generally indicated at C comprises a pair of electrically conducting elongated members 1 and 2 adapted to be detachably and adjustably connected, as will be explained hereinafter. Member 1 is provided at its forward end with a male portion or banana section 3 and member 2 is provided at its rear end with a cylindrical socket 4, the longitudinal ICC 2 axis of the male portion 3 and the socket- 4 being in alignment and the male portion 3 being tapered and reduced in diameter with respect to the rest of member 1 so that it can be received in a socket which has the same diameter as the socket 4. The portion 3 is rounded at its outer end and has longitudinally extending kerfs 5, only one of two being shown, extending at right angles to each other through portion 3 for producing fingers 6, there being four such fingers in the embodiment.

A typical jack, to which the plug of Figure 1 may be connected, is shown in Figure 2, said jack assembly being represented by the letter J and including an elongated member 7 of electrical conducting material, the inner end of which is provided with a depending threaded portion 8 of reduced diameter and the outer end of which is provided with a socket 9. Surrounding the member 7 at the socket area 9 thereof is a sleeve 10 of insulating material having a reduced portion forming a shoulder ii, the reduced portion fitting into a hole 12 in a panel P. Another sleeve 13 of insulating material is adapted to be loosely received on the reduced portion of sleeve ill and sleeve 13 has associated therewith an end portion 14 having an aperture 15 through which the threaded stem extends and depends. With this structure, the jack assembly I, as should be apparent, may be clamped to the panel P by a nut lid on the threaded portion 8 and to connect the jack assembly I to an electrical conductor 17 another nut 18 is employed on the threaded portion'9, said conductor 17 being then clamped between the nuts.

The diameter of socket 9 of jack I may be such, as should be apparent, to receive the male portion 3 of connector C and such a fit will be tight to properly couple the connector to the jack. To further describe the typical parts of connector C, member 2 at the inner end of socket 4 is provided with a threaded bore 19 which is adapted to receive a threaded extension 26) extending from the top of elongated member 1. With this type of construction, an insulating conductor wire 21 may have its bare end 22 positioned between flat surfaces 23 and 24, respectively, which are the bottom and top end surfaces of members 2 and 1 respectively. By screwing members 1 and 9 together a firm clamping on the bare end of wire 22 may be obtained. Member 2 is provided with a sleeve 25 of insulated material and this sleeve may be moulded directly to the member 2 or moulded independently thereof and slid thereon. In order to hold the sleeve 25 on the socket member 2, flange means 26 is provided and the sleeve also has a slot 27 through which the wire 21 extends.

My improved connector means is illustrated in Figures 2, 3 and 4 wherein there is also shown the typical jack assembly I which may be used with the novel plug structure to provide the combined electrical connecting means. The connector C has been described to illustrate other banana type units that may be used with jack assembly J.

Referring particularly to Figures 2, 3 and 4, the plug structure identified generally by letter C, is constructed so that it can be firmly locked in socket 9. The construction shown comprises a cup-shaped member 30 preferably made from suitable insulating material and the bottom of this cup-shaped member is provided with a threaded hole 31 so that the member 32 of electrical conducting material can be threadedly attached thereto adjacent one end thereof. The member 32 which forms the male portion of the connector is of generally tubular construction-in the form of an expansion plug having a portion which is to extend beyond the bottom of the cup-shaped member 30 longitudinally cut to provide a plurality of circumferentially arranged fingers 33. Positioned within the fingers is a rod 34 of electrical conducting material which extends outwardly through the end of the member 32 into the cup-shaped member. The end of the rod within the fingers is provided with a cam portion 35 which is arranged to co-operate with tapered surfaces 36 on the inner sides of the fingers 33. With this cam and the tapered surface arrangement on the fingers, it will be seen that the fingers can be expanded outwardly in a radial direction whenever the rod is pulled inwardly from a posi tion where the cam is adjacent the outer end of the fingers. When the cam is at the outer end of the fingers, they will be radially retracted to their innermost condition, as shown in Figure 2, and under such condition the fingers can be inserted in a socket 9 of a jack I. When the rod is pulled rearwardly from the position shown in Figure 2 the fingers will be expanded and forced tightly against the inner surface of the socket 9 and thus have a very tight frictional grip on the surface of the socket which will be sufiicient to cause a locking action. Figure 3 shows the expanded condition with the connector out of a jack socket.

On the end of the rod 34 which extends into the cupshaped member 30 is secured a cylindrical member 37 of electrical conducting material and this member is provided with a socket 38 which can receive a male portion of various types of connectors such as, for example, the connector shown in Figure l, or a plug connector of the locking type which is being described. In order to attach the member 37 to the rod, the member has a bore 39 extending from the inner end of the socket on through the member 37. This bore receives the end of the rod 34 opposite cam portion 35 and to hold the rod in position it is riveted over as indicated at 441. The inner end of the member 37, when attached to the rod, will project within the Walls of the cup-shaped member 30. The member 37 is provided (by any suitable means) with a sleeve 41 of insulating material such as plastic or rubber.

The connector illustrated in Figures 2, 3 and 4 is also so constructed to have connected therewith a conductor wire 42 which will be connected independently of the socket 38. The bare end of this wire is arranged to extend into a transverse bore 43 which intersects the bore 39. To hold the wire in position a screw 4-4 (see Figure 4-) is threaded into the member 37 at right angles to the transverse bore 43. In order that the conductor wire may have free movement with respect to the cup-shaped member 30 when the member 37 and the rod 34 are shifted longitudinally to perform the locking function, the wall of the cup-shaped member has a slot 45 through which the conductor can extend. The conductor will be in this slot under all axial positions of the member 37, regardless of whether the fingers are expanded for locking in a socket or released for insertion or removal from a socket. The wire, besides being protected, will prevent rotation of the member 37 relative to the cup-shaped member.

In the connector disclosed in Figures 2, 3 and 4, it will be noted that it is capable of establishing multiple connetcions from a jack in the same manner as the plug disclosed in Figure 1, since the connector is provided with a socket and an independent connection with a conductor wire. The conductor wire is readily inserted, due to the screw connecting arrangement. To operate the screw, which is normally within the cup-shaped member, the socket member may be pulled out sufficiently under a strong pulling force, when the connector is out of a socket. to make the head accessible, or the member 32 may be unscrewed from cup 30. It is to be noted that with the attaching arrangement for the conductor, as shown in Figures 2 to 4, it will be possible to attach the conductor by inserting it into socket 38 when such socket is not to be used. The bare end of the conductor Will then be received in bore 39 and be clamped therein by screw 44.

It should be mentioned that further details of construction of jack structure I are shown and described in my application Serial No. 166,049, filed June 3, 1950, and entitled Electrical Jack, now U. S. Patent 2,713,670, issued July 19, 1955.

Being aware of the possibility of various modifications in the structure disclosed and uses thereof without departing from the fundamental principles of the invention, it is to be understood that the scope of the invention is not to be limited in any manner except in accordance with structure called for by the appended claims or equivalent thereof.

What is claimed is:

l. in an electrical connector, 21 cup-shaped member carrying and having depending from the base thereof. longitudinally extending fingers in circumferentially arranged relation, and a second member provided with a portion within the fingers and movable longitudinally relative thereto to cause expansion thereof, said second member extending in part through the base of and beyond the cup-shaped member and being provided in a part thereof with a socket for receiving the male end of another connector, and means operable in another part of the second member for connecting a conductor wire to the second member independently of the socket and at a point within the cup-shaped member, the wall of said cup-shaped member being provided with an opening through which the wire extends and shifts in all positions of the second member.

2. In an electrical connector, a cup-shaped member formed of insulating material, a threaded hole in the base of said member, a hollow member of electrical conducting material threadedly connected in said hole and having depending therefrom and beneath said base circumferentially arranged fingers of electrical conducting material and capable of radial movement to make electrical contact, a second member of cylindrical configuration and of electrical conducting material having depending therefrom a rod of electrical conducting material, said rod having a cam portion at its outer end with the rod and cam being of a size to be received within said hollow member and fingers and moved relative thereto to cooperatively cause radial movement of the fingers, said second member being partially received in said cup-shaped member throughout said relative movement, said second mcmher having a socket for reception of another male member, a transverse bore within the cylindrical member at its area that projects within the cup-shaped member for receiving a wire connector, means to electrically connect the wire connector to the electrical conducting material of the second member, and the wall of said cup-shaped member having a slot therein through which said wire connector passes and can shift during relative movement of the rod and fingers.

3. In an electrical connector, a substantially cup-shaped member formed of insulating material, circumferentially arranged fingers of electrical conducting material and capable of radial movement to make electrical contact depending from the base of said cup-shaped member, a second member including a portion of cylindrical configuration and of electrical conducting material and a rod of electrical conducting material depending therefrom, said members being movable relative to one another, the base of said cup-shaped member having an opening and the fingers being spaced to receive the rod, said rod having a cam portion thereon for cooperatively causing radial movement of the fingers during relative movement of the members, said second member having a socket in a part of the cylindrical portion thereof for reception of another male member and the cylindrical portion of said second member being partially received within the cup-shaped member, and means operable in another part of the cylindrical portion for connecting an electrical conductor to the second member independently that is received within the cup-shaped member, for receiving the conductor and a screw-like member to electrically connect the conductor to the electrical conducting material of the second member, the wall of said cupshaped member having a slot therein through which said conductor passes and can shift during relative movement of the members.

5. An electrical connector as defined in claim 3 wherein the wall of the cup-shaped member is provided with a slot through which the electrical conductor passes and shifts during relative movement of the members.

References Cited in the file of this patent UNITED-STATES PATENTS 1,731,661 Howenstein Oct. 15, 1929 2,713,670 Koch July 19, 1955 FOREIGN PATENTS 621,584 France Feb. 7, 1927 

